I.

Introduction

Video Recording, process of recording images electronically. Two basic technologies—analog and digital—exist to record video images. Analog recording translates an electronic image directly into varying patterns of magnetized metallic compounds on magnetic tape or disc. Digital recording first processes an image electronically into information in the form of 1s and 0s; the information may then be stored on a computer hard drive, on magnetic tape, or as a microscopic pattern on a plastic disc such as a DVD. High-definition versions of digital video (HDTV) recording are now widely used for professional television production. Video recording can be done for broadcasting, playback, editing, webcasting, or archiving.

The techniques used to record images in various video formats share some similarities with those used to record sound (see Sound Recording and Reproduction), and images and sound are usually recorded simultaneously for video recordings. The production of video recordings also retains some general features found in motion pictures and still photography that use photographic film to record images photochemically.

Initial recording of a video image requires some form of video camera or a computer program that generates and records images. A video signal can be recorded with an analog or digital device that receives the signal by antenna, through a cable, from a satellite receiver, or from a direct link to a video camera.

Video recordings typically are viewed with a television screen or a computer monitor. They may also be watched on a personal media device. Video images can also be projected onto a larger surface such as a movie screen. Videotape recorder/playback systems for home use are usually connected directly to a television receiver. Unlike motion picture film, a video recording does not require processing, and so it may be played back immediately. This makes possible the so-called instant replay common to televised sporting events.

A wide variety of video recording formats exist. Most analog recording formats have become obsolete with increasing adoption of digital formats and technology. Digital recording has many advantages over analog recording. In principle, data in digital form can be copied or edited without losing information. The data can also be easily manipulated with computer programs to alter images, add effects, or adjust color or brightness. By contrast, copying and editing analog video by rerecording degrades the signal. However, when digital recordings are compressed some original data is deliberately left out. Compression makes the data easier to store, to send, or to view. Digital signals are much less affected by interference from outside radio or microwave sources.